The Brasfield rift and South Shetland trench are part of the active margin of the Antarctic continent. From the records of a seismic station at the King George Island installed by the Observatorio Geofísico del Uruguay, 3186 seismic events during August 26 and September 11, 2020 were retrieved with an average of 187 earthquakes per day and a maximum of 359 on August 30. 217 events with a local magnitude of ≥4 were well recognized and located by a single-station method. The events show that an earthquake swarm close to the South Shetland Islands and at a short hypocentral distance (~25 km) to the station occurred in August of 2020. The earthquakes in the swarm are near Orca seamount and the listric normal faults, with a ENE-WSW trend of the Bransfield Basin, suggesting their volcano and volcanotectonic origin. In addition to the swarm, several earthquakes in the same time period related to the Artigas Fault with NW-SE trend are also located, which indicates the reactivation of this structure. From all the earthquakes, a relatively high b-value (1.22) is estimated, which might suggest variable resistance for stress accumulation in the Bransfield rift.

布拉斯菲尔德裂谷和南设得兰海沟是南极大陆活动边缘的一部分。根据乌拉圭地理天文台安装的乔治王岛地震台站的记录，检索到 2020 年 8 月 26 日和 9 月 11 日期间的 3186 次地震事件，平均每天发生 187 次地震，8 月 30 日最多发生 359 次。 217个局部震级≥4的事件被单台站方法很好地识别和定位。这些事件表明，2020 年 8 月发生了一个靠近南设得兰群岛且距台站很短的震源距离（约 25 公里）的地震群。布兰斯菲尔德盆地的 ENE-WSW 趋势，表明它们的火山和火山构造起源。除了蜂群，与具有 NW-SE 趋势的 Artigas 断层相关的同一时期的几次地震也被定位，这表明该结构的重新激活。从所有地震中，相对较高的估计b值 (1.22)，这可能表明 Bransfield 裂谷中应力积累的可变阻力。